Siebert attended Western Reserve University (now known as Case Western) but dropped out after two years when her father got cancer. In 1954 she arrived in New York City with $500 to search for a job. She was hired as a trainee research analyst at the Wall Street. firm Bache & Co. She later worked as an analyst at a number of firms. In 1967 she became the first woman to purchase a seat on the New York Stock Exchange (NYSE). For ten years she was the only female among the 1,366 members. In 1969 she became the first woman to own and operate a brokerage firm that belonged to the NYSE, Muriel Siebert & Co, now Siebert Financial Corp. In 1975 when the U.S. government abolished fixed commissions for stockbrokers, Siebert turned her company into a discount brokerage firm. In 1977 she was named New York State banking superintendent. She stepped down in 1982 to run for the senate but lost the Republican primary. Since then Siebert has run her company and been involved with charitable work. She is often called “The First Woman of Finance.”